Windows 8

Error: unknown file system; grub rescue while starting Windows 8

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What is the cause of this error?

The reason for this error is due to the abnormal deletion of a partition where a second/dual OS is installed. For example, this could be a system where you were dual-booting between Windows 8 and Linux, but you deleted the Linux partition. When setting up such a system, each partition contains an MBR (Master Boot Record), which contains vital information on how to boot your operating systems. After deleting the partition or OS, the MBR still contains old boot sector values for both operating systems and booting up can give you an error such as GRUB RESCUE – No Such Partition.

How I can fix the ‘grub rescue’ error?

This article will outline the solution on a Windows 8 system, but the solution is very similar for Windows 7 as well. First you need a Windows 8 (or Windows 7) installation CD/DVD or bootable USB stick.

grub1

Booting into the Windows 8, select Repair your computer.

grub2

If you have created system restore point then use System Restore to restore it without losing your data.

grub3

You can try Automatic repair option first. If it will not work then you need to go with option Command prompt.

Then enter the following commands into the command prompt:

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd

grub4

After executing these commands, you should be able to successfully boot into Windows 8. If you are still having issues, try re-running these steps.

Still having an issue?

If you are still not successful booting into Windows, try the following.

  1. Open the Command Prompt and type: bcdedit
  2. A list of items will appear under Windows Boot Manager and under Windows Boot Loader. Look for following items:
    • Under Windows Boot Manager, the Device item should be set to unknown.
    • Under Windows Boot Loader, the Device and OS device items should be set to unknown.
See also  Windows 8 Start Menu - Love it or Hate it

Run the following three commands to correct the settings:

bcdedit /set {default} device partition=c:
bcdedit /set {default} osdevice partition=c:
bcdedit /set {bootmgr} device partition=c:

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55 thoughts on “Error: unknown file system; grub rescue while starting Windows 8”

  1. Awesome, this worked for me on win 7. Spent hours futzing with recovery disk without success until I found this article

    Thanks heaps

  4. Thanks and that worked for me. Had same trouble and was clueless until I found this. That fixed issue in few minutes while I had wasted few hours fixing other ways (without success) before this article.

  9. I am unable to get into the boot menu,was removing
    Ubuntu partitions but now I dont have a bootloader.. I tried to repair it using windows 8 bootable pen drive as my disk drive is faulty..but I am left with error: no such partition..
    Grub rescue..have tried ls commands also..but stuck at the grub rescue page.plz help

  12. Hey Chris, Please give me the process you used to recover windows 7 on the said topic, i am still stack on the same problem.

    Kiromo

  17. Pingback: How To Fix Vmware Grub Error 17 in Windows

  24. i cant boot from the windows8 installation disc.and in the grub rescue mod it always shows unknown file system after trying for all drivers.how can i fix it ?? any one please help

  27. I tried al these steps above, but with the last one:

    change the bootmgr to partition c:

    The system could not find anything. Files corrupted?
    The problem is still alive.

    Any solutions, please?

  29. This did not work, I cannot load from the Windows 8 disk it still goes to grub rescue, cannot figure it out. I am getting pissed off at the computer along with trying to find the right solution.

  31. I need help immedietly.
    I had kali linux and windows 8.1,i formatted linux partition from windows and restarted than grub rescue mode opens and for every partition it shows unknown file system.and nothing is getting booted like win7 cd,usb stick.
    PLEASE I NEED SOME ADVICE INSTANTALY.

  38. Windows 8.1 system in error:unknown file system entering rescue mode…..
    In my Loptop is very important in our helps in use for I am veten

  43. I had kali linux and windows 10.
    formated linux partition from windows and while restart it shows grub rescue no such partition how can i now fix it
    please help me

  46. Thanks a lot.. You saved me.. Gud Job bro.. Keep it up of making new articles for those who gets problem in anything…

  50. These methods didn’t work on my laptop …
    I’m stuck in that same black screen it showing error :unknown file system
    Grub rescue….. Its ma misfortune….

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